{"cve":"CVE-2026-1355","nvd":{"published":"2026-02-18T21:16:23.460","modified":"2026-06-17T10:15:39.027","status":"Analyzed","description":"A Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to upload unauthorized content to another user’s repository migration export due to a missing authorization check in the repository migration upload endpoint. By supplying the migration identifier, an attacker could overwrite or replace a victim’s migration archive, potentially causing victims to download attacker-controlled repository data during migration restores or automated imports. An attacker would require authentication to the victim's GitHub Enterprise Server instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.20 and was fixed in versions 3.19.2, 3.18.5, 3.17.11, 3.16.14, 3.15.18, 3.14.23. This vulnerability was reported via the GitHub Bug Bounty program.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:L","score":6.0},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","score":6.5},"cwes":["CWE-862"],"references":["https://docs.github.com/en/enterprise-server@3.14/admin/release-notes#3.14.23","https://docs.github.com/en/enterprise-server@3.15/admin/release-notes#3.15.18","https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.14","https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.11","https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.5"],"products":["github:enterprise_server"],"source":"nvd","synced_at":"2026-10-19T22:23:35.260773158+00:00"},"epss":{"cve":"CVE-2026-1355","score":0.00457,"percentile":0.39627,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}